Sheet metal forming has been used in the industry for years for creating metal parts from a blank sheet metal, for example, automobile manufacturers and their suppliers produce many of the parts using sheet metal forming. There are many steps in sheet metal forming, one of the steps is referred to as hemming. Hems are commonly used to reinforce an edge, hide burrs and rough edges, and improve appearance. One example usage of hemming is to manufacture door panel. During a hemming process, a sheet metal edge is rolled flush to itself. In recent years, one particular type of sheet metal forming is referred to as incremental sheet metal forming. A sheet metal is formed into the final workpiece by a series of small incremental deformations. Generally, incremental sheet metal forming is conducted by connecting a forming tool to a CNC (Computer Numerical Control) machine, a robot or the likes. A load path of the forming tool is therefore predefined.
One example usage of incremental sheet metal forming is for production improvements of parts used in a prototyping or concept vehicle. Due limited quantity of the concept vehicles (sometimes one), it is impractical to create stamping tools for various parts. Incremental sheet metal forming is generally used.
With advent of computer technology, computer aided engineering analysis (e.g., time-marching simulation based on finite element analysis (FEA) technique) have been used for assisting engineers/scientists to design products and manufacturing procedures, for example, sheet metal forming process. In order to capture detailed physical behaviors in vicinity of drastic changes, finer finite element mesh is required. One prior approach is to have a finer FEA mesh for the entire model. However, this technique requires unrealistic long computation time and much larger computational resources due to huge size of the FEA mesh model. Incremental metal forming process is very a very slow procedure, to numerically simulate such as a process sometimes requires many hours of computation time. As a result, prior art approaches are not adequate. It would, therefore, be desirable to have improved methods and systems for conducting a time-marching simulation for obtaining numerical physical behaviors of sheet metal during a sheet metal forming process having a predefined load path.